Using ZMK Studio
You can use ZMK Studio via the desktop application or the web app.
The desktop application allows you to change your keymap using Bluetooth. The web app requires you to connect one half of the keyboard via USB cable.
Make sure to connect your keyboard to your device using Bluetooth
Load ZMK Studio
Select your device within ZMK


Once unlocked you'll be greeted with the overview screen, showing the keymap layout and on the left column the different layers.

Clicking a key brings up the editor area, where you can reassign your key.

Some explanations:
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